Having denied him the Key to Time, the Doctor and Romana are on the run from the Black Guardian. Sending the TARDIS off on remote control to flit around a couple of thousand worlds at random to throw their hunter off the scent, the two Time Lords take refuge in â€œone of the three great periods in Earth historyâ€ – London, England during the roaring twenties.

Leaving the Doctor tinkering with a home made etheric field disturbance detector, Romana pops out to browse bookshops in Bloomsbury. But each of them unbeknownst to the other is drawn into an investigation of the alien incursion in Hampshire. It appears that there is more to gormless toff Reggie Bassettâ€™s Aunt Florence than might at first meet the eyeâ€¦

This story is set during the period where on TV producer Graham Williams and script editor Douglas Adams put their own distinctive mark on the series, and as such the script is written with just the right balance of humour and action (plus a couple of mostly harmless references to Adamsâ€™s more notorious works).

The atmosphere of the story itself feels wonderfully like Douglas Adamsâ€™s spiritual predecessor, PG Wodehouse. The 1920s is an era little explored by Doctor Who on television but is one that suits Tom Bakerâ€™s fourth Doctor down to the ground and he recaptures perfectly the slightly defensive attitude the Doctor displayed at this time when dealing with a companion who graduated from Time LordAcademy with a far higher grade than he did.

Mary Tammâ€™s performance here is pitch-perfect, recollecting the confidence and poise of Romanaâ€™s first incarnation, a strong character who could fly the TARDIS better than the Doctor â€“ it is good to hear more from her than the one season in which she appeared on TV. One of the cleverest parts of the story is the way that she and the Doctor are separated for most of the action and yet both have a hand in defeating Julia Mackenzieâ€™s Aunt Florence in parallel, each of them picking up a human sidekick along the way.

The experience of listening to this play (and its successors in this second season of Fourth Doctor Adventures) is lent an unavoidable melancholic atmosphere by the knowledge that Mary Tamm died shortly after completing this series of audios. The tribute to her by Tom Baker in the additional material at the close of the disc is moving and appropriate.